Apparatus and method for tapping molten material from a rotary kiln



R. E. BOEHLER APPARATUS AND METHOD FOR TAPPING MOLTEN May 9, 1961 MATERIAL FROM A ROTARY KILN 4 Sheets-Sheet 1 Filed Dec. 2, 1954 IINVENTOR.

May 9, 1961 R. E. BoEHLI-:R

APPARATUS AND METHOD FOR TAPPING MOLTEN MATERIAL FROM A ROTARY KILN 4 Sheets-Sheet 2 Filed Deo. 2, 1954 INVENTOR.

Maly 9, 1961 R. E. BOEHLER 2,983,501

APPARATUS AND METHOD FOR TAPPING MOLTEN MATERIAL FROM A ROTARY KILN Filed Deo. 2, 1954 4 Sheets-Sheet 3 May 9, 1961 R. E. BQEHLER 2,983,501

APPARATUS AND METHOD FOR TAPPING MOLTEN MATERIAL FROM A ROTARY KILN Filed Deo. 2, 1954 4 Sheets-Sheet 4 1N V EN TOR.

///5 .477'04Q/VEK A .NMSSQ fomz@ TEN MTEHALRMAIRQTARYKILN Robert ,E.Boel1ler,`iG ary, to 'iiited States This invention 'relates to an improved apparatus and method for tapping molten material from a rotaryl kiln.

Although myY invention isfnot limited tota'ppin'g any specific material, :an example' of an operation where itis particularly usefulis in themanufacture of'calcium aluminate cement. i Suchr cementl commonly is produced in Aa rotary kiln'heated'to about 2500" F. The cement is` molten at thi s tter'nper'ature"r but freezes 'if the temperature drops to about 2300 F; The kiln has a tap hole which is openedv periodically for tapping; but which is plugged with clay afterrtapping'is completed.' The" conventional practice has been to ysrtop'the kiln-after approximately each 25 minutes of' operation, open the tap hole with a jackhammer, turn A'the kilnt #place vthe'open tap hole at -Ithe underside,V and fallow molten" clinker to flow from the hole for 'about iive minutes Ybefore resuming operation. The clinkercommonly is received in a pan conveyor where'it freezes in large chunksthat are diicult to crush. j The time consumed in tappingv is ofcourse a direct loss'in'productiontime, in-addition towhich there is a vloss'duevto ycoolingfot the kiln.'H H

object 'otjmyjinvention is to provrdean improved apparatus and methodrfortappingmoltenmaterials from a rotary kiln during a portionoieach revolti'onjwithout stopping the'jkiln, thereby' inc reasiirg productions A further object istolprovidean improved-apparatus and method for keeping agtap hole "of a vrotary kiln open so that `lmolten material; discharges. during aportion of each revolution, even -lthcuifglr the material znormally would freeze the holeshut. j j

A further object is to provide ,an improved apparatus and' method for receiving and handling molten material tapped froma kiln to'profdu ceafgranulated'producten' solidi`ficatio'x1."v t,

A more specic object is.toprovide,"in combination with a rotary kiln, aL device forentering the tap holeonce each kiln revolution to' maintai f the holeopen so that discharges mat'erial'whenever it rotates to the lower-part of the Ikiln,' and' aV specially constructedfscrew conveyor located under the kiln forre'ceiving moltenmaterial-'and granulating the materialfas'it 5501idiefs'f;y .ai '-f 1 Other objects are to provide, as subcomb'inations ot the foregoing, rst adevice' for Aperiodically entering a 'I tap holeY and keeping itl open, audsecond-.an .improved screw conveyorlfo'r receiving .-molte'n material.E andgranulating the material as' it solidities..1 l s l In accomplishing. these. and other .objects of the {inventionyl have provided improved details of structure, a preferred form of which is `shown inthe .accompanying drawings, in which: :1 1 .f r1

Figure 1 is a .side elevationaly viewlof a rotary kiln and receiver to which my tapping device caribe applied;

' Figure 2 isv averticalsectional view on line II-II of Figure l'with the Vtapping -deviceinstalled;I Y

Figure 3 is a verticalsectional view on alarger scale on line III--III of Figure 2;- 1 y Figure 4 is a top plan viewothe tappingvdeviceyf L..

Patented May 9, 1961 5 Figurel7 is--a'crrcit diagram. i

tary kiln which, apart from details hereinafter pointed fout, lcan fbe of any standard or desired construction. 10 '--When Vused'n the .manufacture of calcium aluminate ce- -ment', the kilnY commonly has a steel shell and a refractory lining of cement produced inthe kiln and frozen on thejinnerv surface' of theshe 'Ihe' outside commonly lis'water cooled' to assist in freezing this lining. Nor- 1li'A mally .the kiln is driven in a clockwise direction, as viewed 'in Figurev2, at a'relatively slow substantially constant speed by any suitable drive mechanism not shown, although the ldrive mechanism is capable lof varying the speed vor reversing the direction of rotation. The kiln slopes toward'E its exit end, and is red from a burner 12 at this end in the conventional manner. A pool of molten material M is formed within the kiln. The kiln has ian outwardly ilared tap hole 13 near its exit end. Even if not plugged, the tap hole soon would freeze over along withA the lining.

'' In accordance with my invention, a device 14 for entering the tap hole once each kiln revolution is situated f on the downwardly rotating side (Le. the right as viewed in lFigure 2).v The supporting frame yfor/the device includes a beam 15 on whichv a depending swivel yoke -16 is pivoted to turnon a substantially vertical axis. The yoke includes a horizontal pivot plate 17 and a pair of spaced' apart vertical side vplates 18 which can be adjusted [longitudinally of said pivot'plate. The 'yoke supports a 355 tilt channel 19, which has a pair of trunnion plates 20 Apivoted to the side vplates 18 of the yoke tof-turn on a substantially horizontal axis. The undersideof the tilt channel carries-a double-actingpneumatic cylinder- 21, which isi located between thetrunnionplates and thekiln and has back and front ports 22 and 23 respectively for admitting and discharging compressed air. The other end yof the tilt channel carries a vcounterweight 24, which "slightly overbalances the cylinder 21 and its associated parts,'hereinafter described. reciprocable piston and piston rod 25 are mounted in 'rthe cylinder 2.1. 'The' end of' the'piston rodadjacent the "kilntcarries a'plunger seat 26 in'which a'cylindrical fiplunger"v 27 -is fixed.'- "To guidemovement Aof' the piston rod and plunger, the piston rod preferably carries an upstanding crosshead 28 that rides in a guide 29 fixed to the bottom of the tilt channel 19 (Figure 3). The swivel yoke 16 and tilt channel 19 normally occupy `a position with respect to the vbeam =15 suchthat theplunger is in 1 the sameA vertical plane as thetap hole 13 whenever the 5' latter rotates to -this side of the kilnf Since the kiln slopes, the vertical'plane ofthe tap hole of course varies during kiln'rotation. The k*pivotalconnection between 'theyoke= land beam `15A alsoallovvs the plunger to fol- "lowthetap hole when the; flatter 'moves-'horizontally 6 Thebaek marrant ports zzf'aaa fzs ofthe cylinder 21 are connected via suitable conduits with asolenoid operated four-,wayivalve 30.* Thelatterl is connectedto a compressedair supply via a conduiti31"and also has an exhaust. Normally the valve 30 connects the fron-t port 23 with the air supply and connects the back port 22 with thev exhaust to hold the piston rod 25 and plunger 27 A retracted. Once each kiln revolution, when the -tap hole 13 moves into alignment with the plunger 27.', a timing 70 device hereinafter described operates the valve 30 to ad- 'mitair to the cylinder 2 1 in the reverse direction and thus move the `plunger 27 ipto the tap hole.` An instant later Figures 1 and 2 show somewhat diagrammatically a ronel 19 on the. yOlte 16 on ,a'radiusof Ythe kiln.

vlinks 40. The lever 39 t mences thus to swing,

.swings free1y`-with the kiln.

the timingdevice returns the valve. to normal position to retract the plunger. The kiln continues to rotate while this action occurs. The pivotal mounting of the tilt chanallows the plunger .-to gswing lwith the kilngthroughthe s rnall angle necessary for-the plunger to enter the tap hole briey. The ared shape of thetap hole ,allows some tolerance in the fangle [the plunger assumes with respect to the kiln when the plunger is within the .tap hole; that is, ,the plungergneed not lie exactly To minimize .any :chance of misalienment. I ,prefer t0 startthe plungerturning withlhe kiln before theplunger Aenters .the tapfhole. For :this ,purpose .the .kiln -Shell carries a lng ,3 2 lorigituiinally` o tfset from vthe tap Ahole (Figure l), andthe tapping l,de-vice 1 4 includes a cooperating trip mechanism. The flatter comprises alongitudinal shaft; 33 jonrnaled in a plurality -of Aaligned brackets 34 whichare mounted'on the supporting-beam 15,and also 'en asecond s uch beam laspacedcfrom `the former beam (Figures 3 and 4). The-shaft 33 carriesa triparm 35, which isf located in a position where the lug 32 can engage it, andan operating arm36, both arms beingxed on the shaft. The hack end of the trip varm restspn an ladjustable stop 37 ,0n the beam 15av and carries a counterweight 38 (Figures 2 and '4). vA lever 391s piyotedtothe underside of `the beam and is connected to the operating-armo-of theshaft 33 through preferably is sectional to permit adjustment in i ts,le ngt h. A roller 41 isjournaled to the lever39 f atgiis joint with the links 40. The extremity of thetiltchannel19 carries aroller plate 42. v The counterweight 2 4 on-the tilt-channel normally holds the latter in a position-where the vroller Vplate v42 engages the roller 41, that is, atthe starting end of thepath ,of movement of vthe tilt channel. l 4 l mto alignment with the plunger- 27, the` lugy 32 engages through it. Thenparts .are (proportioned so that the amount of material discharged each revolution approximately equals the amount melted, whereby the pool level at the conclusion of each discharge cycle remains substantially constant.

. Figures 5 and 6 show a preferred receiver for cooling and granulating the material discharged from the kiln .10.` The receiver compri/ses a waterqcooled conveyor screw 50; V which is journaleclin a'box S1-beneath tap hole portion of the kiln. The axis of Y the screw is at right angles to the kilnaxis.V Thegscrew-isdriven Ycontinuously'in a countercloc'kwise ldirection las'viewed in Figure 6 `by .a,motor 53 (Figure 2) locatedj at the end away from which the material travels. The peripheries of the-screw blades advantageously carry hard material, for example, of the cobalt-chromium-tungsten alloy sold under the trademark Stellite.2 Likewise the faces ofthese'blades canlcarry radialjbeads of Water bottom receives vthe screw SOErather closely, .there v-being a clearance between `the bottom .and the periphery-ofthe '-screw .of .about a ,half inch. .Cooling -\vater is introthe Vtrip arm 3S. Thereupon the trip arm 35 vcf mmences i to turnfthe shaft 33 counterclockwse. The operating Aarm 36 acts throughthe links 40 to push. the lever Y39 downwardly. 'Ihe 4roller 41 in .turnpushes the tilt channel 19 downwardly. Shortly after thelplunger V,cornthe timing mechanismactsto push it Ainto the tap hole. After the plungerrenters, the lugk32 moves away from the trip arm 3'5, and the tilt channel The lug 32 mustof course be offset longitudinally frortithetap hole a su`icientfdis tance that it clears the tilt channel 1 9 and -theplungerAZT l as itmoves past. However. the, exitfend Porti@ .ofthe Akiln is the hottest part and subie@tQQnSdereble' Warpage. Iherefore, 1 I.prefer.to locatethe lugas uiicient distancefrom the tap hole thatsuch warpage doesn'ot,

interfere with .itsfacton l l v l A s a safety-feature, the piston rod 25 preferably extends through the back of the cylinder 21 and carries a microswitch l3nt its back end. l'lfhepiston rod and back portion of the plunger 27 together contain avcontnuous longitudinal bore. A in this bore and extends from ther-plunger tothe microswitch. As long gas "the plunger is' properly seated on the vpiston yrod, the `rod 44 exerts l.pressureon the microswitch and' holds it closed. Y

rod ceases to exert pressure onthe .microswitch and .allows the latter to open. The microswitch is connected in the drive circuit :to the kiln, and the kiln immediately stops when the. switch opens.

At the timev the plunger 27Eenters the tap hole 13, the material at the hole is partially frozen, 'but still suflciently soft that the plunger can break through and open the hole; `Shortly after .plunger retracts, the hole rotates to 'a position where'molten material M can ow out to a receiver beneath. The -tl1rough-approximately the `next-120 .of kiln rotation, the hole remaining 4open as long as material is owiing Igf the plunger breaks tf for any reason, such as misalignment with `the tap hole,"I the slender rod 44 is `slidablyV mounted material discharges I speed operation of the screw. To .providefaproper Y charges.

are mechanically connected 'to `,the

duced periodically .tothe water jacket 55V viaan' inlet .56

and discharges over the-blades of the vscrew 510 through two series of .sprayholes 57,y which :are-.located on opposite-sides of the screw in vstaggered relation. The top of the boxlcarriesa splash guard .5 8 vto ,permit high granu- V lating action Son the `material discharged 4into the conveyor,

I prefer to ,operatefthelscr'ewat.arateof about 250 .r.p.n1. ThisY speed .is .considerably `abovekthe critical .at which centrifugal v.force would throw the material out. `For l example, the .critical speed' cfa 12 inch' diameterV screw conveyor: vis 'about .76 Vr.p.m. However, the splas'hguard Acatches- V.the `material `and retains ,itin the conveyor.,

The portion of the .box 51-under th orbit. of the tap hole 13 is open `to ,receive A'molten ,materiallfas it? disy'Since the' discharge .takes ,place 'through approximately rotation Aof .the kiln, .the fopening necessarilyfis .of .considerable flength. "The tming ,mechanismist'ar'tsv waterftlowing 'finto fthefirilet ,56`vjus't before o material commences ,to ,dischargefrom the tap .hole and 'o cuts off the water fatter ,the ,discharge cycle .is y. cfompleted. .The .material solidities in .the `conveyor"and v becomes granulated. It lis then pushed out the end 4intoa-pitS?.

figure 1:"7 shows s chematicallya preferred ,control c'ir- -Vcuit for both the. tapping-device 14,a`1id t`l1`ewat`e`r ,to the screw conveyor. "whose primary winding isOnnected to rv"a" s'u'italalezoutsideV power source. .Oneend ofthe lsecondary winding is groundedland t'helother'V is connected' to a'n1ain.switch Atiti whichfis .closed .to set upgthe mech ariisrn for operation. A'p'ai'r of tinrcdiskso? .and- .68 for @thetalpping device 'and-,the water to the screw conveyor respectively kiln tdrixeansi rotate at the same speedga'sthegkiln. i; The timer disk 67 -forgthe tapping devicewcarries a .grounded contact arm 6.9 whichengages a tixedcontact '.70 when .the plunger ,27 Ais ,in line iOnee'nd of the coil of :a relay :with fthetap Enola 15. is connected ,to the main switch 66 and the other-fend' is-connected to .fthe Icon- .tact 70. 4Consequently relay Apcks iu'p', when `.the ann 69v Tengages :this contact l.but :otherwise .drops out. The lfour-.way valve30 .has fan operating .solenoid L71, one .end of which is grounded and the other :end .of AWhichjis Yconnected to the main switch 66 via aiset .of-.normally open contacts of.` the relay .AQ When the .relay picks .up and -its Acontacts close, the .solenoid .is :energized and :shifts the position of .the yvalve. 30. The cylinder .21 projects the' plunger' 27 into the .tap Thule. '.fHowever,y:the vcontact arm `69 engages the :contactf70 .only -momentarily, so Vthat relay-.A .quicklydrops out,; Vand :the .solenoid '71 an edging of eration o f the tapping device.

is deenrgized andthevalve 30 returns to its normalpo- .-sition'to retractthe plunger. v f

y nected in serieswith the Vvcoil of relay A. As long as the kiln is drivenin-its normal direction, relay Bis energized andits contacts remainclosed to allow regular op-l If the kiln is driven in reverse, relay B drops out'to prevent relay A from picking up. Consequently the tapping device is in eiect disconnected and does not interfere with reverse driving of the kiln. v .L 1

One side of the microswitch 43 is connected to the main switch. 66 and the otherside is connected to the coil of a relay C. The other end of this coil s grounded. Relay C has a set of contacts which are connected in series with the kiln drive. As long as the microswitch is closed, relay C is energized and its contacts are closed allowing the kiln to operate. kIf the microswitch opens, relay Cl drops out and the kiln stops.

The timer disk y68 for the water to cool the screw con-- veyor carries a grounded contact segment 72 which is :adapted to engage a iixed contact '7 3.v The parts are adjusted so that the segment 72 engages the contact 73 -just before material Y commences to flow from the tap hole 1 3 and d isengagesafter suchiiow ceases.` ,One end of `the coilof a relay D isconnected to the main switch 66 and the other end 'is connected to the contact 73. Consequently relay D picks up when the segment 72 engages thisl contact, but' otherwise drops outg Relay D has a setofv normally open contacts which are connected in series between the main switch l66 and one end Yof a v`solenoid 74, the other end of the latter -being grounded. The solenoid 74 operates an air valve 75, which controls a pressure operated water valve 7'6. Normally the air ,valve 75 is open and admits air pressure to the water valve 76 tookeepthedlatter closed. When relay D picks up and energizes the solenoid 74, the airrvalve 75 closes and-cuts off. the `air to the water valve 7.6. The latter wthen'admitscooling Water to the conveyor box 51 via the -inletf56.` The ow of Awater continues until the contact segment 72 clears the contact 73, whereupon relay D drops `out,vthe solenoid 74 is deenergized, the air valve 75 opens, and the water valve 76 closes.

From the foregoing` description it is seen that my intionl timeand'conservationof heat. The improved revceiver producesv a granulated solidifiedV product, which facilitates4 subsequent-.pulverizing over the usual large chunks produced when the product solidiies. Y

While' I 'haveshown and described only a single embodiment of .the'inventiomit is apparent that modications..

Therefore, I do not wish to be limited to may arise.

thefdisclosure set forth 4but only by the scope of the apl. l`he',co'mbination, with a rotary kiln having a tap l 'hole, oflaiappingy device'comprising a. stationary framev locatedat the side of the 7kiln whichnormally moves downwardly as the kiln rotates, means movably'mounted on saidfrarne .for entering saidtap hole from outside the kilnlwhil'e thekiln is rotating-and thus opening the tap hole, aridA a receiver beneath `the kiln for receiving molten material ilowing from said tap hole while the kiln rotates 1 through a substantial arc' with the tap' hole on the underside.

` 2. The combination, with a rotary kiln having a tap hole, of a tapping device comprising a stationary frame located at the side'of the kilnAV which normally moves downwardly as the kiln rotates, means movably mounted E on .s aidptrarnelfor. entering said tap hole from outside .the-'kie while, the #interesting and this evening the 6 tap hole, means for actuating said entering means during each kiln revolution as the tap vhole travels therepast, and a receiver beneath the kiln forre'eeiving molten material owing from said tap hole during each revolution while the kiln rotates through a'substantial `arc'withthe tap hole on the underside. v n

3. The combination, with a rrotary kilnfhaving a tap hole, lofa tapping device comprising a stationary frame located at the side of the kiln which normally moves downwardly as the kiln rotates, lmeansmovably mounted on said frame for entering saidrtap hole fromoutside the kiln while the kiln isy rotating and thus opening the tapv located at the side of the kiln vwhich normally moves' downwardly as the kiln rotates, means movably mounted on said frame for entering said tap hole from outside the kiln while the kiln is rotating and' thus-opening the tap hole, trip means for'starting said entering means swinging with vthe kiln as the tap hole becomes aligned there- Y with, and timing means coordinated with rotation of said kiln for actuating and withdrawing said entering means while the latter is swinging with the kiln, and a receiver beneath the kiln for receivingmolten material from said tap hole while the kiln rotates through a substantial `arc with the tap hole on the underside.

5. The combination, with a rotary kiln having a tap hole, of a tapping `device comprising a stationary frame located at the side of the kiln which normally moves downwardly as the kiln rotates, a support pivotally mounted on said frame adjacent said kiln to swing through a limited. angle with the kiln, motive means carried by said support, a plunger carried by said motive means and adaptedto enter said tape hole while the kiln -is rotating and thus open the tap hole, and timing means coordinated with rotation of said kiln for actuating said motive means to project and retract said plunger during each kiln revolution as the tap hole becomes aligned with the plunger, and a receiver beneath the kiln for receiving molten material flowing from said tap hole during each kiln revolution while thekiln rotates through a substantial arc with the tap hole on the underside.

6. The combination, with a rotary kiln having .a tap hole, of a tapping device comprising a stationary-frame located at the side of the kiln which normally moves downwardly as the Vvkiln rotates, a support pivotally mounted on said frame adjacent said kiln to swing through'a limited V an gle with the kiln, means normally holding said supportat thes tartingendof its path .of movement, reciproc'able motivemeans carried bysaid support, a plungercarried bysaid motive means and adapted to be operated thereby, and timing means coordinated with rotation of said kiln foractuating said motive means to project said .plunger into said tap =hole when the latter becomes' aligned with the plunger and4 to retract the vplunger while the support is vswinging with the kiln, and' a receiver beneath said, kiln forreceiving molten material flowing from said` tap hole while the kiln rotates Y through a substantial arc With the tap hole on the underside. l

7. A combinationas defined in claim 6 in-Which said tap hole ares outwardly to allow tolerance inthe ap proach angle of said plunger.

8. The combination, with a rotary kiln having a rtap hole, of a tapping device comprising astationary frame located at the side of the kiln which'normallyjmoves downwardly as the kiln rotates, a support pivotally monntedon-saidfr'ame adjacentsaid kilnto swing through a llimited angle ywith Lthejfkiln, `means normally holding A-`Said support at the's'tarting end of-"its path of movement,

reciprocable motive means 'carried by said support, a

plunger carried lby lsaid motive -rneans andadapted to be operated thereby, trip means pivoted to said frame and engaging said support, 'means on the kiln for operating said trip means -to swing 'said-support* and-said plunger with the Vkiln as saidtap hole becomes aligned with said plunger, and timing means coordinatedl with rotation of said kiln vfor actuating'saidfrnotive means to project said plunger into said tap hole and retract it while the support ris swinging with the kiln, and Ya receiver beneath said kiln for receiving Imolten material owing from said tap hole while the kiln rotates through a substantial arc Vwith the tap hole on the underside.

9. The combinatiom'with a rotary kiln having a tap hole, of a tappingdevice comprising a stationary framev located ,at theside vof the kiln which normally moves downwardly as the kiln rotates, a support pivotally mounted on said frame-adjacent said kiln to swing through a limited angle vwith the kiln, means normallyholding said support at the starting end of its path of movement,

' a double-acting pneumatic cylinder carried by said support, a plunger carried by said cylinder and adapted t enter said tap hole while the kiln lis rotating and thus to open the tap hole, tripmeans pivoted to said frame and engaging said support, `means on the kiln for operating said-trip means during each kiln revolution to swing said support and-saidplunger with the kiln each time said Atap hole lbecomes aligned with said plunger, and timing hole, of a tapping device comprising a stationary frame v located at Athe side of the kiln which normally movesk downwardly 'as-the kiln rotates, means movably mounted on said framefor entering said tap 'hole from outside the kiln while the lkiln isrotating and thus opening-the V-tap hole,and a water-cooled screw conveyor beneath 'the kiln having its axis at-right angles to that of the kiln, said conveyor being adapted to receive molten ma- .terialowing from said tap hole while the kiln rotates through a-substantial arc with the taphole on the underside-and to granulate the material as it solidiies.

1v1. The combination, with va rotary kiln having a tap Y. hole, of a tapping device comprising a stationary frame `.located at the side ofthe kiln -whichnormallymoves downwardlyas thekiln rotates, #means movably mounted on said -frarne for ventering said -taprhole-from outside the ykiln while the kiln is .rotating and thus opening the tap'hole, means -for actuatingjsaidentering means during each` kiln 4vrevolution-ias the tap hole travels therepast,` and a `Water-'cooled screw conveyor beneath :the kilnhav- 5 ing its axis at right anglesto that of the kiln, said conl veyor having lan .opening of substantial-length to receive molten material flowing from Vsaid tap hole during each kiln revolution while thekiln rotates through a substan- -.tial ,arc withthe `tap hole .on the underside and being adapted to granulate the material as it solidiies.

12. The combination, with a rotary kiln having `a tap hole, of a tapping device comprising a stationary frame located at the side of the kiln which normally movesl downwardly as the kiln rotates, means movably mounted on said frame for entering said taphole from outside the ,kiln while the kiln is rotating and thus opening the tap hole, land timing means coordinated with rotation of said` kiln for actuating and 'withdrawing said entering means`v 8 during-'each kiln revolution as lthetap Alho'letravels therepast, and a water-cooled .screwconveyorbeneathfthekiln having -its -axis atl right angles to that Aofi thefkiln, said n 'conveyor 'having an opening of substantial-length to receive molten material iiowinglfrom'said tap holeduring each'kiln revolution while the kiln rotates'through a -substantial arc with the tap hole on the underside 'and beingadapted to granulatelthe material as it lsolidiics,

and additional timing means coordinated with rotation of said kiln'for starting ow of cooling water to said conveyor ahead of the flow of material-from said tap hole and cutting ol ow of water after flowrfrom the'rtap hole 13. A device for entering the tap Ihole of a -rotary kiln while the latter is rotating comprising a stationary-frame, a support pivotally mounted onsaidframe, reciprocable motive means carried -by said support', -a plunger carried by said motive means, trip means carried by said `frame land cooperable with vsaid support to swing the support and plunger vwith the kiln as the tap hole thereof becomes aligned with said plunger, `and timing mechanism adapted to beV connected with the kiln foractuating said motive 'means to project and retract said plunger while said support and plunger are swinging.

14. A device as definedin claim V13 -in'which swinging i movement of 'said support isconiined'to a limited angle Vand including means normally vholding said support at the starting end of'its pathof movement. s

15. A `receiver for vmolten material from a rotary kiln comprising a conveyor screwfabox having a rounded bottom housing said screw, a water jacket on the outside of vsaid rounded bottom, said bottom having openings for discharging water from said jacket over said screw, a `guard xed to the top of said box over saidscrew allow- 'ing the latter'to rotate at speeds above the critical while retaining material therein, the rtop of said box having an elongated opening alongside said guard toadmit molten material, and means for driving said screw.

16. A tapping device comprising mechanical means for entening a tap hole in the side of a lrotary kiln whilethe latter is rotating, a'statio'nary fname mountingsaid mechanical means for limited Vrotational movement with the a stationary frame `mounting said entering and motive Vmeans for limited rotational ymovement 4with the kiln, trip means for moving said `entering and motive means with theY kiln as the tap hole'comes Vinto alignment withsaid entering means, and timing means elective to fopenate said motive means to move said entering means linto and out of the tap hole during their'limited movement ywith the kiln.` i-

18. A tapping device comprising a stationary frame, a support mounted on said frame for swinging movement, motive means carried by said support, means operated by said motive means for entering a tapvhole'in the side l of a rotarykiln lto clear the hole of frozen-material, swinging movement of said supportenabling said entering meansV p to move with the tap Vhole .whillethe kiln is, rotating, timing means `for starting -operation of said motive' means as the tap hole rotates into .alignment with said entering means, and means for thereafter returning said support toits star-ting position. v

19. A tappingdeVice comprising `a stationary frame, a support mounted on said frame for swinging movement .on both horizontal and vertical axes, motivemeans carried by said support, a plunger operatedby said motive means and adapted to project Vinto a --tap hole in the side of a ,rotary 'kiln and retract and thus clear'thehole of frozen material, Aswinging movement of said support enabling said plunger to enter the tap `hole and move therewith while 9 the kiln is rotating, timing means for starting operation of said motive means as the tap hole rotates into alignment with said plunger, and means for returning said support to its star-ting position after said plunger'retracts.

20. A tapping device comprising la stationary frame, a support mounted on said frame for swinging movement, motive means carried by said support, means operated by said motive means for entering a tap hole in the side of a rotary kiln to clear the hole of frozen material, swinging movement of said support enabling said entering means to move with the tap hole while the kiln is rotating, trip means cooperable with said support to start it swinging as the tap hole rotates into alignment with said entering means, timing means for starting operation of said motive means after said support commences to swing, and means for thereafter returning ysaid support to its starting position.

21. A tapping device comprising -a stationary frame, a support mounted on said frame for swinging movement on both horizontal and vertical axes, motive means carried by said support, a plunger operated by said motive means and ladapted to project into a tap hole in the side of a rotary kiln and retract and thus clear the tap hole of frozen material, swinging movement of said support enabling said plunger to enter the tap hole and move therewith while the kiln is rotating, trip means cooperable with said support -to start it swinging as the tap hole rotates into alignment with said plunger, timing means for starting operation of said motive means after said support commences to swing, and means for returning said support to its starting position after said plunger retracts.

22. A tapping device as defined in claim 21 in which said trip means includes a shaft journaled to said frame, a trip arm and an operating arm fixed to said shaft in spaced apart relation, and levers connected to said operating arm and said frame and engageable with said support when a rota-ting kiln engages said trip arm.

23. A method of tapping molten but easily frozen material from a' rotary kiln comprising clearing the tap hole of the kiln of frozen material by entering it during a portion of each kiln revolution while the kiln is rotating and as the tap hole is moving downwardly approaching the underside of the kiln, =and receiving molten material owthe underside of the kiln during each kiln revolution and v while the kilniis rotating through a substantial arc.

24. In the operation of a rotary kiln having a tap hole in its side wall, `a method of tapping molten material which tends to freeze and close the tap hole comprising mechanioally entering the hole and thereby clearing it of frozen material during a portion of each kiln revolution While the kiln is rotating and -as the tap hole is moving downwardly approaching the -underside of the kiln,l and receiving molten material flowing from the cleared tap hole when the latter rotates to the underside of the kiln during each kiln revolution and while the kiln is rotating through a substantial arc.

25. In the operation of a rotary kiln having a tap hole in its side wall and wherein molten material in the kiln freezes over the tap hole as the tap hole is moving upwardly and across the upper side of the kiln, a method of tapping molten material from the kiln comprising mechanica-lly entering the tap hole land ythereby clearing it of frozen material during a portion of each kiln revolution while the kiln ris rotating and as the tap hole is moving downwardly approaching the underside of the kiln, and receiving molten material flowing from the cleared tap hole when the latter rotates to the underside of the kiln during each ki-ln revolution and while the kiln rotates through a `substantial arc.

References Cited in the tile of this patent UNITED STATES PATENTS 56,595 Morris et =al July 24, V1866 433,136 Peck July'29, 1890 1,117,644 Donaldson Nov. 17, 1914 1,186,358 Witz June 6, 1916 1,361,103 Scott Dec. 7, 1920 1,373,581 Wurst Apr. 5, 1921 1,455,313 Vreeland May 15, 1923 1,916,402 Allen July 4, 1933 2,057,099 Ingraham Oct. 13, 1936 2,404,650 'Newkirk et al. Juiy 23, 1946 2,410,236 Reaney Oct. 29, 1946 

